That's my guess, I don't know if that was the reason or not. It's a background. So when would you count something as a background? When not?
Also, in backgrounds you could also accidentally have something in there that the contest organizers didn't notice. And they already had enough to do just figuring out who stole images and who ripped off stuff.
Rip offs were taken out, as you can see that they removed no 12 in the female section.
If you can prove that the other things are rip offs (aka not only used as a reference but being too similar or even being traced), SE will probably remove those too. But you have to prove it.
Edit: Well, maybe it's not the background then.
But the "too long" is a rule for this competition. Doesn't matter if there are long hairs ingame already.
And if you look at the template, the hair would be outside of the picture.
Personally, I would have loved to see very long hair

But rules are rules.